Conventionally, an EGR device that recirculates a portion of exhaust gas from the exhaust path of the internal combustion engine to the intake path as EGR gas has been provided to internal combustion engines. An EGR valve that adjusts the flow rate of EGR gas flowing inside of an EGR path is arranged midstream of the EGR path in which the EGR gas flows in the EGR device.
If this EGR valve is arranged in the vicinity of the intake path, which is the outlet of the EGR path, blow-by oil having flowed through the intake path may enter inside the EGR path, adhere to the EGR valve, and the valve function may no longer be able to be exhibited.
As technology addressing such a problem, the technology described in Patent Document 1 provides a curved part (hereinafter referred to as “oil collector”) at a position closer than the position of the EGR valve, by way of the EGR path sloping downwards as distancing from the EGR valve, and subsequently sloping upwards towards a surge tank. According to this technology of Patent Document 1, if the blow-by oil in the form of a mist in the blow-by gas returned to the surge tank enters the EGR path, it will drip downwards along the inner wall surface of the EGR path, and collect in the oil collector at the lowest part. Adherence of the blow-by oil to the EGR valve is thereby prevented, whereby the matter of the EGR valve not being able to exhibit a valve function is prevented.
[Patent Document 1] Japanese Patent No. 3424720